/**
  @page RCC_Example RCC example
  
  @verbatim
  ******************** (C) COPYRIGHT 2013 STMicroelectronics *******************
  * @file    RCC/RCC_Example/readme.txt 
  * @author  MCD Application Team
  * @version V1.3.0
  * @date    13-November-2013
  * @brief   Description of the RCC example.
  ******************************************************************************
  *
  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
  * You may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *        http://www.st.com/software_license_agreement_liberty_v2
  *
  * Unless required by applicable law or agreed to in writing, software 
  * distributed under the License is distributed on an "AS IS" BASIS, 
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
  ******************************************************************************
  @endverbatim

@par Example Description 

This example shows how to use, for debug purpose, the RCC firmware to retrieve 
the current status and frequencies of different on chip clocks. 
You can see the "RCC_ClockFreq" structure content, which hold the frequencies of 
different on chip clocks, using your toolchain debugger.

This example handles also the High Speed External clock (HSE) failure detection:
when the HSE clock disappears (broken or disconnected external Quartz); HSE, PLL
are disabled (but no change on PLL config), HSI selected as system clock source
and an interrupt (NMI) is generated. In the NMI ISR, the HSE, HSE ready interrupts
are enabled, and once HSE clock recovers, the HSERDY interrupt is generated and in
the RCC ISR routine the system clock is reconfigured to its previous state (before
HSE clock failure). You can monitor the HSE clock on MCO1 pin(PA8).

Four LEDs are toggled with a timing defined by the Delay function.

 @note On the STM324xG-EVAL/STM32437I-EVAL/STM324x9I-EVAL RevB boards,  
       to genertate the HSE failure you can remove the HSE quartz from the socket.
 

@par Directory contents 

  - RCC/RCC_Example/system_stm32f4xx.c   STM32F4xx system clock configuration file
  - RCC/RCC_Example/stm32f4xx_conf.h     Library Configuration file
  - RCC/RCC_Example/stm32f4xx_it.c       Interrupt handlers
  - RCC/RCC_Example/stm32f4xx_it.h       Interrupt handlers header file
  - RCC/RCC_Example/main.c               Main program
  - RCC/RCC_Example/main.h               Main program header file
  
     
@par Hardware and Software environment 

  - This example runs on STM32F405xx/407xx, STM32F415xx/417xx, STM32F427xx/437xx and 
    STM32F429xx/439xx devices.
    
  - This example has been tested with STMicroelectronics STM324xG-EVAL (STM32F40xx/
    STM32F41xx Devices), STM32437I-EVAL (STM32F427xx/STM32F437xx Devices) and 
    STM324x9I-EVAL RevB (STM32F429xx/STM32F439xx Devices) evaluation boards and 
    can be easily tailored to any other supported device and development board.

  - STM324xG-EVAL Set-up
    - Use LED1, LED2, LED3 and LED4 connected respectively to PG.06, PG.08, PI.09
      and PC.07 pins
  
  - STM324x7I-EVAL Set-up
    - Use LED1, LED2, LED3 and LED4 connected respectively to PG.06, PG.08, PI.09
      and PC.07 pins
      
  - STM324x9I-EVAL RevB Set-up
    - Use LED1, LED2, LED3 and LED4 connected respectively to PG.06, PG.07, PG.10
      and PG.12 pins

       	       
@par How to use it ?

In order to make the program work, you must do the following:
 - Copy all source files from this example folder to the template folder under
   Project\STM32F4xx_StdPeriph_Templates
 - Open your preferred toolchain 
 - Select the project workspace related to the used device 
   - If "STM32F40_41xxx" is selected as default project Add the following files in the project source list:
     - Utilities\STM32_EVAL\STM3240_41_G_EVAL\stm324xg_eval.c
        
   - If "STM32F427_437xx" is selected as default project Add the following files in the project source list:
     - Utilities\STM32_EVAL\STM324x7I_EVAL\stm324x7i_eval.c
          
   - If "STM32F429_439xx" is selected as default project Add the following files in the project source list:
     - Utilities\STM32_EVAL\STM324x9I_EVAL\stm324x9i_eval.c
                 
 - Rebuild all files and load your image into target memory
 - Run the example
    
 * <h3><center>&copy; COPYRIGHT STMicroelectronics</center></h3>
 */
